Regarding invite codes, I've proposed using Nostr badges for access control. https://github.com/neilck/nostr-access-control
How would you handle access revocation?
nostr:nevent1qqsvxf0k8p8zvsgxhjvctpn3w3dp30jfqdw6lwghcv8ed8h7fra6ltqpz3mhxue69uhhyetvv9ujuerpd46hxtnfdupzqqqqqqphw4qzgy6etty7zcfta4ggs90f3mz248tg5f3glas4fpt0qvzqqqqqqymz8wzd ?